# Add the root path of the pygra library
import os ; import sys 
sys.path.append(os.path.dirname(os.path.realpath(__file__))+"/../../../src")





# zigzag ribbon
from pygra import geometry
g = geometry.honeycomb_zigzag_ribbon(20) # create geometry of a zigzag ribbon
h = g.get_hamiltonian(has_spin=False) # create hamiltonian of the system
#exit()
h.get_bands()






